Adding Hard Disks - Acer Altos EasyStore User Manual

Appendix B

Adding hard disks

147
The effect of adding hard disks to your storage system varies, depending on the
disk configuration you chose when you configured the system and the current state
of the existing disks.
For example, in a linear configuration, you can add a new disk at any time, and data
can be written to that disk as soon as it is added. (Access to the disks is temporarily
interrupted while the disk is being added.) Whether you previously removed a disk
or one of the other disks failed makes no difference.
In a RAID configuration, the effect of adding a disk varies, depending on whether the
RAID is in a normal or degraded state (as indicated on the Disks page). A normal
state indicates that the RAID is functioning properly. A degraded state indicates that
one or more disks have been removed or failed, but because of the data protection
offered by the RAID, you can continue to access all the data.
In a normal state, you cannot add a disk to a RAID 0 or RAID 1 configuration. Any
disk that you install will not be used unless you subsequently reconfigure the
storage system (as described in
Caution: Reconfiguring your storage system disks deletes all the data on your
storage system.
However, if you currently have three disks and a RAID 5 configuration, you can add
a fourth disk as a spare (essentially changing from RAID 5 to RAID 5 + spare while
retaining all your existing data).
In a degraded state, you can add a disk to a RAID at any time, and the new disk will be
rebuilt to replace the disk that was removed or failed.
Caution: If the RAID has failed—that is, if so many disks have failed or been
removed that the RAID can no longer function—you must either re-install the
disks or reconfigure the entire storage system, deleting all the data on your
system.
Although you can add a disk of any size to a linear configuration, any new disk that
you add to a RAID configuration must be the same size as or larger than the
smallest existing disk in the RAID.
"Reconfiguring your storage system
Disk Configurations
disks").
Altos easyStore Manual